In order to fulfill the basic functions of our service, the user hereby agrees to allow Xiaomi to collect, process and use personal information which shall include but not be limited to written threads, pictures, comments, replies in the Mi Community, and relevant data types listed in Xiaomi's Private Policy. By selecting "Agree", you agree to Xiaomi's Private Policy and Content Policy .

Welcome back to tech class. Our topic for this week's class is about Solid State Batteries.

History:

Let's see a brief history of batteries. In 1800, Alessandra Volta invented the first battery and it was known as Voltaic pile and the unit volt is named after him. Many types of batteries were invented as time passed but they all were single-use batteries. That means they will be exhausted after a single use and cannot be used again.

In 1859, a French physician Gaston Planté invented the first rechargeable battery. It was a lead-acid battery where a spiral roll of two sheets of pure lead, separated by a linen cloth and immersed in a glass jar of sulfuric acid solution.

In 1899, the Nickel-Cadmium(NiCd) battery was invented Waldemar Junger who is from Sweden. But why stop there? Nickel-metal hydride(NiMH) battery was invented in the 1970s and commercially made available in 1989. They had better energy density when compared to NiCd batteries. NiMH also contained less toxic materials when compared to NiCd ones.

In 1991, Sony released the first Lithium-ion(Li-Ion) battery. The power density offered by Li-Ion is much higher than the previous types of batteries. The rate of self-discharge is also lower but they are costly and needs protection from over-charge and over-discharge. Besides powering cellular phones, laptops, digital cameras, tools and medical devices, Li-ion is also a candidate for vehicles. Li-ion has a number of benefits including a higher energy density, is easier to charge and does not have maintenance issues, unlike nickel-based batteries.

Recently, nickel–metal hydride and lithium-ion batteries have become commercially available and cheaper, the former type now rivalling Ni-Cd batteries in cost. Where energy density is important, Ni-Cd batteries are now at a disadvantage compared with nickel–metal hydride and lithium-ion batteries. However, the Ni-Cd battery is still very useful in applications requiring very high discharge rates because it can endure such discharge with no damage or loss of capacity.

Let us now talk about the major advancement in battery technology – Solid State Batteries. In a conventional battery design, two solid metal electrodes are used with a liquid lithium salt acting as an electrolyte. Ionic particles move from the cathode to the anode as the battery charges, and in reverse as it discharges. The liquid lithium salt electrolyte is the medium that allows that movement.

In a solid-state battery, both the positive and negative electrodes and the electrolyte between them are solid pieces of metal, alloy, or some other synthetic material. Solid-state batteries are also safer, since there’s no toxic, flammable liquid to spill, and they don’t output as much heat as conventional rechargeable batteries.

In 2013, researchers at the University of Colorado Boulder announced the development of a solid-state lithium battery, with a solid composite cathode based upon an iron-sulfur chemistry, that promised higher energy capacity. In 2014, researchers at Sakti3 announced a solid-state electrolyte lithium-ion battery and claimed higher energy density for lower cost. The company was acquired by Dyson in the following year. In 2017, John Goodenough, a co-inventor of Li-ion batteries, unveiled a new solid-state battery, using glasselectrolytes and an alkali-metal anode consisting of lithium, sodium or potassium, which is not possible with conventional batteries.

Saving Space – As solid electrolyte replaces conventional liquid electrolyte, it saves a lot of space because the size of separators can be reduced. An electric car with a solid-state battery could remove all the cooling elements in favour of a larger battery, and therefore longer range, or reduce the size of the battery while retaining the same range and cutting the cost.

Longer lifespan- Solid state batteries are less reactive and last longer than current batteries and hence need not be replaced every 2-3 years. According to the latest research, a solid-state battery could outperform conventional rechargeable batteries by 500% or more in terms of capacity, and charge up in a tenth of the time.

Safer- Solid State batteries are considered safer are they are not flammable as batteries with liquid electrolytes.

Fast Charging- These are believed to have very high fast charging capacities. In addition, higher voltage and longer cycle life are possible with solid-state batteries.

Cost- The major disadvantage of solid state batteries is costs they are very expensive to make.

Temperature- Operating these in low temperatures might be a challenge as they have very poor performance.

Materials- Another issue is the materials. While the properties of various metals, alloys, and metallic salts used for conventional rechargeable batteries is well-known, we don’t currently know the best chemical and atomic composition for a solid electrolyte between metallic anodes and cathodes.

Availability- Currently, the research is still going on regarding solid-state batteries and it takes considerably long enough for their commercial availability.

When can I use a solid state battery?

Still, the latest research is finally producing results that can compete with existing Li-ion batteries in terms of attributes, while also providing the benefits of solid-state electrolytes. All we need is for manufacturing processes to mature, and there are a number of large and upcoming battery manufacturers with the resources to make this a reality.

Toyota and Dyson both believe solid-state batteries could be in final products by 2020, but there’s no guarantee this will happen. As ever with technology, there’s a huge difference between a technology that works on a small scale and one that’s ready for mass-market production.

Conclusion:

Depending on the technical advancements and success rate of research conducted by various companies, we can expect solid-state batteries in five or ten years. It may also take 20 years, but when we finally get to see solid-state batteries it is going to be a major breakthrough as it offers up to 6 times faster charging, up to twice the energy density, a longer cycle life of up to 10 years compared to 2, and no flammable components. Let us hope for a less battery hungry future with these solid-state batteries.